Bleaching- of ghaut by sulfuric acid



UNITED sTATEs PATENT oEEioE.

JAMES M. CLARK, OF PHILADELPHIA, PENNSYLVANIA.

IBILEhLCI-II1\TGr OF GRAIN BY SULFURIC ACID.

Specification of Letters Patent No. 27,887, dated April 17, 1860.

T o all 'whom 'it may concern:

Be it known that I, JAMES M. CLARK, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented or discovered a Mode of Bleaching YVheat and Rye; and I do hereby declare that the following is a full, clear, and exact descrip-t tion of the principle or character which distinguishes it from all other things before known, and of the usual manner of making, modifying, and using the same.

My invention or discovery consists in eX- posing wheat and rye to the action of sulfurous acid gas so as to whiten the grains thereby enhancing the value of clark-colored, discolored, or damaged grains and also improving the flour from such grain. known that what is called red wheat in commerce is richer in gluten than white wheat, although the latter is preferred on account of its appearance. Dark grain and dark flour are objected to merely on account of appearance, and so universal is this prejudice against dark flour and dark bread that bakers resort to deleterious art-s to make white bread from dark flour. Hy discovery of whitening the grain in the kernel will thus contribute to the health of communities by dispensing with the necessity of adding drugs to flour, and will make dark grains equal in value to the white grains.

In order to whiten red wheat I pass the grain through an atmosphere of sulfurousacid gas, which bleaches the kernel, remov ing all discoloration and without any injury whatever to the grain. The flour of this bleached grain has a fair white appearance and is not affected in any way injuriously by this treatment. The gra-in is agitated in a screen or other suitable receptacle for a sufficient time in the gas; and various methods may be resorted to for exposing the grain uniformly to thev action of the bleaching agent.

The machinery for bleaching is described and represented as follows.

A is a screen mounted upon suitable bearings so that it may be revolved within the casing B. The bearing is in the wall of the casing and the bearing D is of peculiar construction, so as to admit the grain to the screen from the spout E. The shaft or axis of the screen enlarges at F into a collar which embraces and turns upon the spout E and this collar is provided with openings in its circumference through which the grain It is well a thorough agitation and exposure 0f the grain to the bleaching atmosphere of the casing .or compartment in which the screen re volves. On the outside of the screen are wings or carrying pieces K which being set obliquely and in different directions on different halves of the cylinder conduct the v screenings to the central escape pipe L.

The bleaching atmosphere is obtained and regulated as follows: M is a stove, N its lire chamber and P the smoke pipe shown in dotted lines. R is a division plate upon which sulfur is sprinkled and as it burns, the sulfurous-acd gas arising therefrom passes up into the casing B and through the meshes of screen A and bleaches the grain. The air for supplying the combustion of the sulfur is admitted to the gas generating chamber G, and regula-ted through the valve S. The sulfur is conveyed to the plate R through the passage T. The quantity is regulated as follows: The shoe al under the hopper,

' which receives the sulfur, is agitated as follows: V is a wire connected with the shoe -and also with springs IV and X. The

spring W is so arranged that when the band wheel Z revolves its spokes strike the spring and push it out of the way. At the same time the spring X draws upon the wire and gives motion to the shoe and when the spoke has' passed the spring W, falls back again and gives motion to the shoe in an opposite direction. The vibration of the shoe is shortened or lengthened by turning the regulating stem a, around which the wire passes, and thus regulates the quantity of sulfur falling from the shoe into passage T. The sulfurous-acid gas passes out of the casing B through pipe d into the grain receptacle b from which it escapes through the pipe d1. The receptacle b or chamber into which the grain falls from the pipe e embraces part of casing B and is intended to be close, so as to prevent the escape of the acid fumes, except at the discharge pipe Z1 and is furnished with suitable means of entrance or man hole at f and discharge of the grain at g. The gas and grain may both be discharged at pipe e in which case the pipe l must be closed. The hopper h, through which the grain passes,4 to spout E, is movable up and What I claim as my invention and dis- 10 down and having its lower end cut off covery is obliquely at la, the amount of grain passing The bleaching of wheatl and rye by exposmay be regulated'by raising or lowering the ing the same to the action of suliulzous=acl.4 hopper7 and is fiXed at any desired height gas substantially as heiein above set forth.

by the set screw m. JMES M. CLARK.

It will be seen that the operation of this VVitnesses:

machine upon the grain is twofold, cleans- CHAs. G. PAGE,

ing it by screening as well as bleaching it. WM. H. HARRISON. 

